This invention relates to a detent mechanism for a hand held powered tool; more particularly, to a detent spring molded as part of a plastic housing to provide detents and an audible indication when traversed in either direction by a slide button having a projection with tapered sides engaging the spring.
The prior art in detent mechanisms for hand held powered tools has provided for a separate spring and screw for retaining the same to a molded housing. Such a device is disclosed and described in U.S. Pat. No. 3,729,822, which relates to a sabre saw having a saw bar which is manually rotatable and selectively lockable about its own axis to set the cutting edge of the saw blade in different angularly oblique positions relative to the line of movement of the tool. A control knob is coupled to the saw bar by means which allow the saw bar to reciprocate within the control knob. Turning of the control knob will cause a like turning of the saw bar. A lock pin is transversely slidable with respect to the control knob and is carried by a slide button mounted in the handle of the housing. When the lock pin is in an unlocked position, the control knob can be manually manipulated. However, when the lock pin is in a locked position, a tapered tip thereof will lock the control knob by engagement with angled slots in an external flange of the bushing for the saw bar, so as to prevent turning of the control knob. In the prior art U.S. Pat. No. 3,729,822, the slide button is retained in the locked or unlocked position by a keeper implemented by a light leaf spring which cooperates with tapered sides of the slide button to define a particular position. This light leaf spring is retained to the tool housing by a screw. The difficulties with this arrangement are the cost of the screw and of the leaf spring, plus the cost of assembling the spring to the housing. Further, variability in manufacturing of the leaf spring frequently causes the detent to be excessive or insufficient at times, necessitating disassembly of the housing and reforming or replacing of the leaf spring until a proper detent is attained.